This award will support collaborative research between Dr. Thomas Gallagher, University of Virginia and Dr. Pierre Camus and Pierre Pillet, Laboratoire Aime Cotton, Orsay, France. The objective of the project is to study highly correlated atomic systems in which two of the atomic electrons are in similar orbit. Atoms with two highly excited, correlated electrons present one of the major challenges to present day atomic physics. Although there have been many theories proposed, there remains very little experimental information to guide the formation of the theories. The investigators propose to study such atomic states experimen- tally. Specifically, they propose to use multistep laser excitation of Ba atoms, which have two valence electrons, coupled with state selective detection of the doubly excited states. Such studies, using rather different techniques, are currently underway in both laboratories. By combining the approaches and exploring new avenues, the investigators expect to be able to view the doubly excited atoms from different perspectives, gaining valuable new insights into their properties and guiding future theoretical developments. Both the US and French groups have substantial research records in the study of highly excited states in general, and have developed many of the techniques upon which the proposed program rests. In addition, both research groups have ready access to theoretical groups with expertise in correlated atomic systems.
